The present invention relates generally to mechanisms for coupling micro-components, and more specifically to microcomponent interconnection utilizing post-assembly activation.
Extraordinary advances are being made in micromechanical devices and microelectronic devices, including micro-electro-mechanical devices (MEMs), which comprise integrated micromechanical and microelectronic devices. The terms “microcomponent,” “microdevice” and “microassembly” are used herein generically to encompass microelectronic components, micromechanical components, MEMs components and assemblies thereof. Generally, microcomponent devices have feature dimensions that are less than about 1000 microns.
Many methods and structures exist for coupling MEMs and other microcomponents together to form a microassembly. One such method, often referred to as “pick-and-place” assembly, is serial microassembly, wherein microcomponents are assembled one at a time in a serial fashion. For example, if a device is formed by coupling two microcomponents together, a gripper or other placing mechanism is used to pick up one of the two microcomponents and place it on a desired location of the other microcomponent. These pick-and-place processes, although seemingly quite simple, can present obstacles affecting assembly time, throughput and reliability, especially when electrically interconnecting microcomponents during microassembly.
For example, it is commonly accepted that about 1 mN of force is required to achieve an electrical contact of sufficiently low resistance between two gold conductors. However, many existing microassembly procedures, including some pick-and-place procedures, operate with application forces much lower than 1 mN. Thus, many existing microassembly procedures do not provide adequate electrical interconnection of microcomponents, thereby reducing the fabrication yield and assembly reliability.
To overcome this disadvantage, microcomponents may be temporarily positioned for coupling, such that electrical contacts to be coupled are in contact with one another, and electrical current may be provided to the contacts. Consequently, localized heating may occur and the contacts may diffuse with one another. As a result, an electrical interconnection of sufficiently low resistance may be achieved between the coupled microcomponents without requiring the 1 mN of force typically required for microassembly.
However, many microcomponents are not designed to withstand the electrical current required to achieve the localized heating necessary to adequately interconnect the microcomponents. Moreover, such a method is labor extensive and consumes part of the useful life of the microcomponents and assembly.
Accordingly, what is needed in the art is a microcomponent assembly and interconnection method that addresses the above-discussed issues of the prior art.